This invention relates generally to devices for taking measurements in blood, such as measuring platelet function or aggregation, and more specifically to an electrode assembly used in the devices for measuring platelet function or aggregation.
Platelets are a type of blood cell that plays a role in wound healing. There are various stages during healing of an injury, including hemostasis (i.e., blood clotting), during which platelets in the blood attach to or aggregate at the site of the injury. For example, the attached platelets undergo various changes to stimulate clotting, including changing into a different shape and releasing chemical signals promoting clotting. Given these known normal responses for platelets to various aggregating reagents, responses of platelets in blood to those aggregating reagents can be tested and observed to reveal disorders, dysfunction, and normalcy of a person's platelet function. One method for testing platelet aggregation is the impedance method, or impedance aggregometry method, where platelets in anti-coagulated blood are held and stirred at a specific temperature of 37° C. in a cuvette or other suitable container that includes an electrode. Impedance measurements between two wires of the electrode are taken for various mixtures of the platelets and aggregating reagents. Conventional devices set up for the impedance method include an electrode assembly that can be placed in the cuvette including the platelets, but conventional electrode assemblies have various limitations. For example, the conventional electrode assemblies include flexible, non-rigid substrates along with wires that are minimally anchored, and hence do not allow for consistent reproducibility of placement of the wires relative to each other on the electrode assemblies and relative to the cuvette in which the electrode assembly is placed for measurement. In addition, the signal to noise ratio for conventional electrode assemblies is mediocre. Conventional assemblies can also be difficult to manufacture.